Earlier quoted context omitted.
> The web needs independent browsers...[websites] should work on any browser Unfortunately, independence ends with the choice between WebKit (QtWebKit) or Blink (QtWebEngine), albeit with a faithful Opera 12-like interface that's less resource hungry than Vivaldi. Otter is still in development and it shows in some rough spots and occasional crashes.
QtWebkit has been deprecated for a long time, and removed from Qt6. If you use it, you'll run into 'not supported' messages on most Google websites.
Doesn't change the fact that it's been deprecated/removed upstream, though, unfortunately.